How does driving affect your engine power at great heights? This is what you need to know – Jalopnik

Think back to the science lesson at school. You were learned that the earth is a huge sphere with a thin layer of atmosphere over it. Despite some flat Earthers claim, the air that we breathe does not need a container, because gravity itself is the container. (If you have to remind us of being a sphere, look at live streams of the earth of the ISS and witness the curve.)

Despite the edge of the room with a name (the Kármán line), there is no difficult, defined definition between “air” and “no air”, but more a general area around 50 to 62 miles up where airtightness is so low, aircraft cannot stay up. Air pressure drops as the earth’s surface falls further from the earth’s surface, and although the pressure on sea level is 14.7 pounds per square inch, it is only about 60% of that Peakes Peak in Colorado on top.

Cars need air like people do, but the symptoms of altitude sickness present themselves differently between you and your Honda. Although you become dizzy, nauseous and weak, your car will just become weak. The general rule is that every 1000 feet that you climb, your car loses 3% of its horsepower. A 300 hp 1995 Mustang Cobra R at sea level, for example, will only earn 210 hp at 10,000 feet. If you are going to ride at great heights for a longer period of time, owners of older carburated cars (or new carburated cars for you fans of Cobra and 356 replicas) must rearrange your carbohydrates, including changes, to compensate for vaccum pressure drops.

Even if those oxygen atoms do not want to enter the combustion rooms of your car, they do not have much choice if you have a turbocharger or supercharger. Forced Induction makes it at least possible to get the conditions needed to compensate for the height -related power loss. Unfortunately, turbo compressors and superchargers are non-intelligent pieces of machines and boost Willy-Nilly will produce if it is allowed. To compensate capital losses at greater heights, one of the two scenerios must be done.

In scenario one, the engine uses strict computer control to check any aspect of the performance, so that it can compensate for the variance of the air pressure. The vehicle must be able to compare the gas valve position and the engine speed, know whether the engine runs too rich or too lean and arrange how much pressure to release from the Wastegate, if present. Turbo -Washing sates regulate boost pressure, which is great because you don’t want wild boost to destroy expensive parts. (And yes, you can use a Wastegate with a supercharger; Engine -boning Reports that Stenod’s performance has done it with centrifugal superchargers.)

In scenario two, the car with turbocharger or supercharged is set to work permanently at a certain height. For example, if you have a supercharged car at 10,000 feet, you can change belt rolls to change the amount of boost to your motorcycle, so that you have the same power as your friends at sea level. Mathematics among you can even find out how much boost you need with the Performance trends blazer boost calculator.

Air warms up when it is compressed, and in gasoline engines this can become a problem. Between piston compression and spark plug -plug inflammation, drops of the air/fuel mixture can explode when and where they feel. The higher the compression ratio, the greater the chance that this will happen. This phenomenon is called knock, detonation or ping. Of course serious knock may sound like harmless, distant, crackling, but it can crack or blow pistons.

Fortunately, gasoline with raised oct assessments are beating in motors with high compression and even lets your Ford EcoBoost engine actually make its advertised horse power. Octane is not a substance or additive, it is an assessment of the stability of a fuel and its resistance to unwanted combustion.

As the height increases, less oxygen comes in your engine, which means that the chances for beating fall. So, your engine can have compression that would be quite high at sea level (for example 12: 1), but with the reduced oxygen content it would not need fuel with a high octane area, because the atmosphere itself will reduce the compression ratio. So, at some more raised locations of America, fuel stations will wear 85 octane gas. If your car is going to make less power, why wouldn’t you fill it with Cheapo Gas, right?

No, don’t do it! Modern automated engines are designed for specific operational windows, and if 85 is not in that window, you ask for problems (it is certainly not in the case of Ford). Low-Octaan 85 is a by-product of an era in which carburded engines handle it well, but that era is over. So do your car a favor. If you ever make a road trip over a mountain, it feeds it with the octane rating it deserves.